Persist Environment in metadata (#1741)

* environment metadata spec

* persisting env in metadata

* Changelog entry

* docs

* typo

* derive TypeInfo for chain extension

* address clippy complaints

* remove unnecessary borrow

* add comments

* typo

Author: German

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Persist `Environment` in metadata - [#1741](https://github.com/paritytech/ink/pull/1741)
+
 ### Changed
 - Upgraded `syn` to version `2` - [#1731](https://github.com/paritytech/ink/pull/1731)
 

crates/env/Cargo.toml

@@ -16,7 +16,6 @@ categories = ["no-std", "embedded"]
 include = ["Cargo.toml", "src/**/*.rs", "README.md", "LICENSE"]
 
 [dependencies]
-ink_metadata = { version = "4.1.0", path = "../metadata", default-features = false, features = ["derive"], optional = true }
 ink_allocator = { version = "4.1.0", path = "../allocator", default-features = false }
 ink_storage_traits = { version = "4.1.0", path = "../storage/traits", default-features = false }
 ink_prelude = { version = "4.1.0", path = "../prelude", default-features = false }
@@ -56,7 +55,6 @@ ink = { path = "../ink" }
 [features]
 default = ["std"]
 std = [
-    "ink_metadata/std",
     "ink_allocator/std",
     "ink_prelude/std",
     "ink_primitives/std",

crates/env/src/types.rs

@@ -177,6 +177,7 @@ pub trait Environment {
 }
 
 /// Placeholder for chains that have no defined chain extension.
+#[cfg_attr(feature = "std", derive(TypeInfo))]
 pub enum NoChainExtension {}
 
 /// The fundamental types of the default configuration.

crates/ink/codegen/src/generator/chain_extension.rs

@@ -133,6 +133,9 @@ impl GenerateCode for ChainExtension<'_> {
         let instance_ident = format_ident!("__ink_{}Instance", ident);
         quote_spanned!(span =>
             #(#attrs)*
+            #[cfg_attr(feature = "std", derive(
+                ::scale_info::TypeInfo,
+            ))]
             pub enum #ident {}
 
             const _: () = {

crates/ink/codegen/src/generator/env.rs

@@ -39,6 +39,8 @@ impl GenerateCode for Env<'_> {
             type Hash = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::Hash;
             type Timestamp = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::Timestamp;
             type BlockNumber = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::BlockNumber;
+            type ChainExtension = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::ChainExtension;
+            const MAX_EVENT_TOPICS: usize = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::MAX_EVENT_TOPICS;
         }
     }
 }

crates/ink/codegen/src/generator/metadata.rs

@@ -28,7 +28,10 @@ use quote::{
     quote,
     quote_spanned,
 };
-use syn::spanned::Spanned as _;
+use syn::{
+    parse_quote,
+    spanned::Spanned as _,
+};
 
 /// Generates code to generate the metadata of the contract.
 #[derive(From)]
@@ -96,6 +99,7 @@ impl Metadata<'_> {
             ::ink::LangError
         };
         let error = Self::generate_type_spec(&error_ty);
+        let environment = self.generate_environment();
         quote! {
             ::ink::metadata::ContractSpec::new()
                 .constructors([
@@ -113,6 +117,9 @@ impl Metadata<'_> {
                 .lang_error(
                      #error
                 )
+                .environment(
+                    #environment
+                )
                 .done()
         }
     }
@@ -407,6 +414,35 @@ impl Metadata<'_> {
             )
         })
     }
+
+    fn generate_environment(&self) -> TokenStream2 {
+        let span = self.contract.module().span();
+
+        let account_id: syn::Type = parse_quote!(AccountId);
+        let balance: syn::Type = parse_quote!(Balance);
+        let hash: syn::Type = parse_quote!(Hash);
+        let timestamp: syn::Type = parse_quote!(Timestamp);
+        let block_number: syn::Type = parse_quote!(BlockNumber);
+        let chain_extension: syn::Type = parse_quote!(ChainExtension);
+
+        let account_id = Self::generate_type_spec(&account_id);
+        let balance = Self::generate_type_spec(&balance);
+        let hash = Self::generate_type_spec(&hash);
+        let timestamp = Self::generate_type_spec(&timestamp);
+        let block_number = Self::generate_type_spec(&block_number);
+        let chain_extension = Self::generate_type_spec(&chain_extension);
+        quote_spanned!(span=>
+            ::ink::metadata::EnvironmentSpec::new()
+                .account_id(#account_id)
+                .balance(#balance)
+                .hash(#hash)
+                .timestamp(#timestamp)
+                .block_number(#block_number)
+                .chain_extension(#chain_extension)
+                .max_event_topics(MAX_EVENT_TOPICS)
+                .done()
+        )
+    }
 }
 
 #[cfg(test)]

crates/ink/src/lib.rs

@@ -36,6 +36,8 @@ pub use ink_env as env;
 pub use ink_metadata as metadata;
 pub use ink_prelude as prelude;
 pub use ink_primitives as primitives;
+#[cfg(feature = "std")]
+pub use metadata::TypeInfo;
 
 pub mod storage {
     pub mod traits {

crates/metadata/src/lib.rs

@@ -36,6 +36,8 @@ pub use self::specs::{
     ContractSpec,
     ContractSpecBuilder,
     DisplayName,
+    EnvironmentSpec,
+    EnvironmentSpecBuilder,
     EventParamSpec,
     EventParamSpecBuilder,
     EventSpec,
@@ -51,6 +53,7 @@ pub use self::specs::{
 
 use impl_serde::serialize as serde_hex;
 
+pub use scale_info::TypeInfo;
 #[cfg(feature = "derive")]
 use scale_info::{
     form::PortableForm,